<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <title>Document</title>
  </head>
  <body>
    <!-- 准备好一个容器 -->
    <div id="test"></div>

    <!-- 引入react核心库 -->
    <script type="text/javascript" src="../js/react.development.js"></script>
    <!-- 引入react-dom, 用于支持react操作DOM -->
    <script
      type="text/javascript"
      src="../js/react-dom.development.js"
    ></script>
    <!-- 引入babel, 用于将jsx转为js -->
    <script type="text/javascript" src="../js/babel.min.js"></script>

    <script type="text/babel">
        //创建组件
      class Demo extends React.Component {

        handleSubmit = (event)=>{
            event.preventDefault() //阻止表单提交
            const {username,password} = this
            alert(`你的用户名为：${username.value},密码为：${password.value}`)
        }

        render() {
          return (
            <div>
                <form onSubmit={this.handleSubmit}>
                    <input type="text" ref={c => this.username = c} name="username"/>
                    <input type="text" ref={c => this.password = c} name="password"/>
                    <button>提交表单</button>
                </form>    
            </div>
          );
        }
    }
    //渲染组件
    ReactDOM.render(<Demo/>,document.getElementById('test'))
    </script>
  </body>
</html>
